The purpose of this research is to explore further the relationship of Epstein-Barr virus (EBV) and of its clinical expression, infectious monocucleosis, (IM) to Hodgkin's disease (HD). It has already been shown that antibody titers to EBV are significantly higher in patients with HD, both prior to and subsequent to therapy, than in matched controls and that there is a 2-3 fold increase of HD following IM. The aims of the current study are 1) to determine if EBV antibody levels are elevated in pre-diagnostic sera from cases of HD as compared to controls, 2) to show viral specificity by lack of elevation to other herpesviruses, 3) to show disease specificity by the lack of EBV antibody elevation in non-HD lymphomas and leukemias. To achieve these aims sera from healthy persons who later developed HD will be tested along with matched controls. These sera have been identified in 5 large serum collections in the U.S., Norway, and Sweden in which follow up has been possible either through a linked cancer registry or through medical records in a pre-paid health plan. A few pre-diagnostic sera from nasopharynteal cancer (NPC), and EBV-related malignancy are also available for testing to determine if antibody elevations to EBV precede the disease.